Department of
Environmental Quality

As the agency responsible for protecting Idaho's surface water, DEQ continually monitors and assesses the quality of the state's rivers, streams, and lakes. This information is used to report to the U.S. Environmental Protection Agency and to make decisions regarding water quality management.

How Monitoring and Assessment Protect Water Quality

Protecting Idaho's surface waters is a continual process. Most steps in this process involve monitoring or assessing water quality or using the results of the monitoring and assessment to report on the quality of Idaho's waters, write water quality plans (total maximum daily loads), or write and implement implementation plans. The success of those plans is evaluated through more monitoring and assessment. The primary steps in this process are described below.

The Monitoring and Assessment Process

Step 1. Collect Data

The Surface Water Ambient Monitoring Plan outlines DEQ's approach to collecting and integrating ambient water quality monitoring data from a variety of monitoring programs, including the Beneficial Use Reconnaissance Program (BURP), National Aquatic Resource Surveys, Trend Monitoring Network, and special studies.

DEQ's BURP program sends crews into the field to collect water temperature data, biological samples (e.g., fish, bacteria), chemical measures (e.g., specific conductivity, the ability of water to pass an electrical current), and habitat data from Idaho 's surface water. The data collected are used to determine whether beneficial uses are being supported in Idaho 's streams, rivers, and lakes. DEQ also collects data through the Trend Monitoring Network. This program, operated by the U.S. Geological Survey in cooperation with DEQ, monitors trends in water quality at 56 sites around Idaho. In addition to its own data collection efforts, DEQ also solicits and considers data submitted from outside sources such as the U.S. Forest Service, the Idaho Department of Fish and Game, and EPA.

Step 2. Assess Data and Determine Beneficial Use Support

Using BURP and other data and the methods described in the Water Body Assessment Guidance (WBAG), DEQ determines if each of Idaho's water bodies meets water quality standards and supports beneficial uses.

Step 3. Write and Submit Required Reports

DEQ is required to submit an “Integrated Report” to the EPA that describes the quality of all of Idaho's water bodies and identifies and prioritizes the state's water quality problems. This report is based on the data collected and analyzed in Steps 1 and 2 and is submitted to the EPA approximately every two years.

Step 4. Evaluate Impaired Waters to Determine Causes and Source of Pollutants

Where water quality fails to meet state water quality standards (as documented in the Integrated Report), DEQ evaluates the water body to determine the causes and sources of pollutants. This is called the subbasin assessment. Additional data are collected to complete the subbasin assessment. This assessment is the first step to either developing a total maximum daily load (TMDL) or recommending removing the water body from the list of impaired waters.

Step 5. Establish Total Maximum Daily Loads for Water Bodies

Using information from the subbasin assessment, DEQ establishes a TMDL for each impaired water body. The TMDL sets maximum allowable levels for pollutants causing water quality violations.

Step 6. Develop an Implementation Plan

An implementation plan is written after a TMDL is developed. The plan provides details of the actions needed to achieve pollutant load reductions and outlines a schedule of those actions. The plan also specifies monitoring needed to document action and progress toward meeting water quality standards.

Step 7. Continue to Monitor and Analyze Water Bodies

The implementation plan specifies monitoring methods to determine if the recommended changes are improving water quality and if and when water quality standards are being met. If a water body was found to be meeting water quality standards in Steps 2, 3, or 4 (that is, no TMDL or implementation plan was written), it will be monitored again in the future to ensure it continues to meet standards.

Invasive Species Prevention

Invasive species are a serious ecological and economic threat to Idaho. Monitoring activities have the potential to spread non-native noxious weeds, pathogens, and exotic flora and fauna among water bodies. Therefore, DEQ has instituted decontamination procedures to prevent the spread of invasive species. These procedures must be followed by all DEQ personnel monitoring surface waters.

Beneficial Use Reconnaissance Program (BURP)

The Beneficial Use Reconnaissance Program, known as BURP, is a cost-effective, efficient monitoring survey of Idaho’s streams. The purpose of the program is to collect and measure key water quality parameters to aid DEQ in determining whether a water body is supporting its beneficial uses. Learn more.

Integrated Report

Every two years, DEQ is required by the federal Clean Water Act to conduct a comprehensive analysis of Idaho's water bodies to determine whether they meet state water quality standards and support beneficial uses or if additional pollution controls are needed. This analysis is summarized in an "Integrated Water Quality Monitoring and Assessment Report," commonly referred to as the Integrated Report. Learn more.

Outside Data Policy

During development of the Integrated Report, DEQ actively solicits data from outside sources. Data must be scientifically rigorous and relevant. Examples of acceptable data are Ph.D. or master’s theses, published or printed studies or reports, environmental assessments, and models. DEQ then uses a three-tiered approach to evaluate the scientific rigor and relevance of data submitted to determine where and how it will be incorporated into the assessment process. Learn more.

Use Attainability Analysis

A use attainability analysis (UAA) is a structured scientific assessment of the beneficial uses a water body could support, given application of required effluent limits and implementation of cost-effective and reasonable best management practices. Learn more.